A touchpad on a portable computer is well known. See, for example, U.S. Pat. No. 5,469,194, entitled Apparatus and Method for Providing Different Input Device Orientations of a Computer System, issued Nov. 21, 1995 to Clark, et al. A touchpad on a portable computer is mounted on the same side of the portable computer housing as is mounted a display, such that both the display and the touchpad are visible to the user during operation. Further, a touchpad on a portable computer is coupled to a display such that movement in any given direction on the touchpad corresponds to movement in the same direction on the display, and with relative positioning with regard to movement on the touchpad and movement on the display.
A selective call radio with a contraposed touchpad is known. See U.S. Pat. No. 5,729,219 entitled Selective Call Radio with Contraposed Touchpad, issued Mar. 17, 1998 to Armstrong et al. In a selective call radio with a contraposed touchpad, the touchpad and the display are mounted such that both are not visible to the user simultaneously. Typically, during operation, the display is viewed, and the touchpad cannot be seen--merely felt. Further, a touchpad on a selective call radio with a contraposed touchpad is coupled to the display such that movement along one direction on the touchpad corresponds to movement in an opposite direction on the display, and with absolute positioning with regard to movement on the touchpad and movement on the display.
A single touchpad cannot alternately function as a touchpad mounted on the same side as a display and as a contraposed touchpad mounted on the side opposite the display by simply relocating the touchpad because there is also a need to also change the coordinate systems and the positioning factors.
Thus, what is needed is a selective call radio having a display and a hinged touchpad that can function both in the manner of a touchpad for a portable computer and in the manner of a touchpad for a selective call radio with a contraposed touchpad, depending upon the position of the hinged touchpad.